66872921 has 8 divisors (see below), whose sum is σ = 69324288. Its totient is φ = 64440000.

The previous prime is 66872899. The next prime is 66872941. The reversal of 66872921 is 12927866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66872921 - 2⁶ = 66872857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66872941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2996 + ... + 11946.

It is an arithmetic number, because the mean of its divisors is an integer number (8665536).

Almost surely, 2^66872921 is an apocalyptic number.

It is an amenable number.

66872921 is a deficient number, since it is larger than the sum of its proper divisors (2451367).

66872921 is a wasteful number, since it uses less digits than its factorization.

66872921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9223.

The product of its digits is 72576, while the sum is 41.

The square root of 66872921 is about 8177.5865021411. The cubic root of 66872921 is about 405.8978627138.

The spelling of 66872921 in words is "sixty-six million, eight hundred seventy-two thousand, nine hundred twenty-one".